staphylococcus aureus

The Clinical Lab I work in has had an increase in the number of latex negeative
Staph aureus' the last 3 months,also. We follow up the staphaurex with
microscan identification. They look picture perfect and smell just like Staph
aureus so we call them. They have been both MRSA and not MRSA. It is very
disturbing.
About once a year we see a catalase negative Staph aureus.
Donna